小粒种咖啡主干和一级分枝刮皮有效防治咖啡虎天牛     

Bhat.  PK 刘昌芬 《云南热作科技》1996,19(2):45-48

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杀菌剂对胡椒急性萎蔫病的防效     

Unni.  PK 邢谷杨 《热带作物译丛》1992,(6):15-15,27

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日粮对家畜肠组织总量及肠道功能性工作负荷的影响     

Romp.  PK 胡少昶 《国外畜牧学(猪与禽)》1993,(4):30-33

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印度咖啡产量与生产率的研究     

Rama.  PK 陈泽坦 《热带作物译丛》1989,(3):15-19

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Atomic force microscopy of atomic-scale ledges and etch pits formed during dissolution of quartz     

Gratz AJ  Manne S  Hansma PK 《Science (New York, N.Y.)》1991,251(4999):1343-1346

The processes involved in the dissolution and growth of crystals are closely related. Atomic force microscopy (AFM) of faceted pits (called negative crystals) formed during quartz dissolution reveals subtle details of these underlying physical mechanisms for silicates. In imaging these surfaces, the AFM detected ledges <1 nanometer (nm) high that were spaced 10 to 90 nm apart. A dislocation pit, invisible to optical and scanning electron microscopy measurements and serving as a ledge source, was also imaged. These observations confirm the applicability of ledge-motion models to dissolution and growth of silicates; coupled with measurements of dissolution rate on facets, these methods provide a powerful tool for probing mineral surface kinetics.  相似文献   

Atomic-resolution electrochemistry with the atomic force microscope: copper deposition on gold     

Manne S  Hansma PK  Massie J  Elings VB  Gewirth AA 《Science (New York, N.Y.)》1991,251(4990):183-186

The atomic force microscope (AFM) was used to image an electrode surface at atomic resolution while the electrode was under potential control in a fluid electrolyte. A new level of subtlety was observed for each step of a complete electrochemical cycle that started with an Au(111) surface onto which bulk Cu was electrodeposited. The Cu was stripped down to an underpotential-deposited monolayer and finally returned to a bare Au(111) surface. The images revealed that the underpotential-deposited monolayer has different structures in different electrolytes. Specifically, for a perchloric acid electrolyte the Cu atoms are in a close-packed lattice with a spacing of 0.29 +/- 0.02 nanometer (nm). For a sulfate electrolyte they are in a more open lattice with a spacing of 0.49 +/- 0.02 nm. As the deposited Cu layer grew thicker, the Cu atoms converged to a (111)-oriented layer with a lattice spacing of 0.26 +/- 0.02 nm for both electrolytes. A terrace pattern was observed during dissolution of bulk Cu. Images were obtained of an atomically resolved Cu monolayer in one region and an atomically resolved Au substrate in another in which a 30 degrees rotation of the Cu monolayer lattice from the Au lattice is clearly visible.  相似文献   

Diploid-Triploid Mosaicism: An Unusual Phenomenon in Side-Necked Turtles (Platemys platycephala)     

Bickham JW  Tucker PK  Legler JM 《Science (New York, N.Y.)》1985,227(4694):1591-1593

Diploid and diploid-triploid mosaic individuals of Platemys platycephala were found in natural populations. In mosaic specimens, the blood, spleen, liver, and testis contained both diploid and triploid cells. The ratio of triploid to diploid cells was more variable among individuals than among somatic tissues within an individual. Only diploid cells underwent meiosis in males; haploid gametes were produced. There appears to be geographic variation for mosaicism in that only diploids were found in Bolivia, whereas diploids and diploid-triploid mosaics occured in Surinam.  相似文献   

Tokamak in India     

Kaw PK 《Science (New York, N.Y.)》1996,273(5277):861c

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Methods for evaluating genotype-environment interactions illustrated by laying hens     

Mathur PK  Horst P 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1994,111(1-6):265-288

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What Is Your Diagnosis?     

Morgan SJ  Miller EA  Ewing PJ  Cusick PK 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1994,23(3):69-71

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